Although the grouping seemed interesting at first, it means now our servers don’t fit on our screen anymore.

I would suggest adding a button to the "Group by" header that says "no headers" (or maybe a checkbox somewhere).

This button (or checkbox) would show the "old" layout again with the grouping on the left side as here: https://www.red-gate.com/wp-content/uploads/2019/10/SQL-Monitor.png

There is much more horizontal screen real estate than there is vertical; because of these new grouping headers we now need to scroll to see our DEV servers.

I am fully aware I can click the headers to minimize the content but that's also not what I want because then I'm missing the wait/cpu/disk IO stats on the servers in this group.